The present disclosure relates to a battery housing, having a battery chamber which is sealed to prevent penetration of moisture and which serves to accommodate at least one battery module, and having a pressure equalization device to compensate for pressure fluctuations between the battery chamber and the outside thereof.
Electromechanically driven vehicles, such as passenger cars, floor conveyor vehicles or the like, use battery modules as current storage devices. Such battery modules are typically composed of a plurality of individual batteries. These batteries are so-called high-voltage batteries. There are certain requirements for the housing of the battery modules which are necessary for an operation of such a vehicle. It is essential that the battery module(s) is/are protected in their battery housing from external conditions. In addition, it is necessary to house the battery module or modules in a battery housing which is sealed to prevent the penetration of moisture, so as to prevent condensation inside the battery housing. Moisture which penetrates into the battery chamber of the battery housing can lead to a short circuit and a resulting fire in the battery module.
A battery housing is known from DE 10 2014 215 032 A1, in which a battery module consisting of a plurality of battery cells is accommodated in a watertight manner in a housing formed from pressure plates, U-shaped profiles and covers. This known battery housing has an emergency degassing device which can release gas to the exterior in the event of overpressure arising in the interior of the housing, thereby relieving the overpressure. Such an overpressure can be caused by excessive heating of the battery module. The emergency degassing device is furnished as a gas-permeable but water-impermeable membrane. This membrane can also serve the purpose of creating a constant pressure equalization between the battery chamber and the outside environment. A disadvantage of this known emergency degassing device is that an overpressure in the battery chamber can only be relieved to such an extent as is permitted by the gas-permeable membrane. Such a membrane does not allow pressure reduction in the event of a rapid pressure build-up in the battery chamber. Instead, the battery will burst. The same is true in the case of a vacuum which arises rapidly in the battery chamber—which can occur, for example, after a fire in a cell.
DE 10 2011 109 249 A1 describes a battery housing which has a venting device. This comprises a rupture disk, which bursts when an overpressure is built up. The venting device known from this document does not serve the purpose of establishing a constant pressure equalization between the battery chamber and the outside of the battery housing.
DE 10 2007 063 191 A1 discloses a battery housing which is equipped with an overpressure valve. This opens when there is an overpressure in the battery chamber. It is not possible with the battery housing of this prior art to compensate for a negative pressure which arises in the battery chamber.
DE 10 2013 201 365 A1 discloses a battery module having a degassing channel connected thereto. This enables controlled degassing in the event of an overpressure in a battery chamber, and at the same time enables protection for the remaining battery chambers. However, this process is not reversible, such that there is no constant pressure equalization. In particular, it is not possible to compensate for a vacuum in the battery chamber.
The foregoing examples of the related art and limitations therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.